Popular open source DHCP program open to hack attacks

The makers of the internet's most popular open source DHCP program have warned that it's vulnerable to hacks that allow attackers to remotely execute malicious code on underlying machines.

The flaw, which is present in Internet Systems Consortium's DHCP versions prior to 3.1-ESV-R1, 4.1-ESV-R2, and 4.2.1-P1, stems from the program's failure to block commands that contain certain meta-characters. The vulnerability makes it possible for rogue servers on a targeted network to remotely execute malicious code on the client, the non-profit ISC warned on Tuesday.

ISC advises users to upgrade. Users can in some cases follow workarounds, which include disabling hostname updates or configuring their systems to access only legitimate DHCP servers in settings where access control lists are in place.

Short for Dynamic Host Configuration Protocol, DHCP is a system for automatically assigning computers IP addresses on a given network and helping administrators to keep track of those assignments. ISC says its DHCP program is the most widely used open source DHCP implementation on the Internet.